chore(deps): update dependency org.pitest:pitest-maven to v1.20.6

Author: renovate[bot]

java/pom.xml

@@ -124,7 +124,7 @@
             <plugin>
                 <groupId>org.pitest</groupId>
                 <artifactId>pitest-maven</artifactId>
-                <version>1.20.5</version>
+                <version>1.20.6</version>
                 <dependencies>
                     <dependency>
                         <groupId>org.pitest</groupId>